I will spare you the "How did that happen?" line of questioning because, frankly, it was the constant revolution of the earth around its axis, its continued orbit around the sun, that got us from there — 8 pounds and 12 ounces of you curled against my chest, me not able to feel my feet — to here, this morning, you easily 10 times that size and pressing snooze on your alarm before making your way downstairs to type in your forgotten homework on my computer.

And also, frankly, the past nine years haven’t just flown by in the blink of an eye. I don’t care what anyone says: they took nine years, those years. Those first 10 or so mostly sleepless months may have, in fact, taken a little longer. Maybe you should be turning 9½. But that’s okay — you are, like every other human on this planet, rightfully entitled to your full share of time on this earth, and you, my son, have lived your time fully and passionately and memorably every day of every year of your life until now and I see no reason why you won’t continue to do so, or why I should pretend that I can’t remember any of them. Why wouldn’t I, and why wouldn’t I want to?

That said, I will continue to be frank: in those nine years, there have been sleepless nights and tantrum moments and smart-Alec comebacks that I would not choose to repeat, that I might choose to expunge from the record were such things possible. But they are not, just as the joyful moments are not, and for the most part, we’re good, kid. Welcome to nine, also known as your 10th year, and well played!

The weird thing about this birthday is that I remember me at nine, in fourth grade. And not just hazy, vague memories. Nine was the year our family moved across the country, from Toronto to Vancouver, marking a sort of "before" and after" point in my childhood. I started fourth grade at one school in one city and ended it at another in another, and I have not only clear memories of that shift, but clear memories of my opinions about that shift (I wasn’t happy about it). At nine, I was fully a being in my own right, my agenda and my preferences markedly delineated — if not quite fully separated — from those of my parents.

And I know that’s what’s happening to you. I can see it everywhere: the music you listen to, the conversations with your friends I overhear in the car during soccer carpools, how you come home with information I could never have taught you. You speak French now better and more fluently than I ever have and ever will; soon, I imagine, you and your brother will begin having entire, secret, conversations in front of me and your other mother and we won’t be able to do much about it. You actually have political views, and on occasion, they diverge from mine. Some of your interests — to wit, Pokémon, soccer — also diverge markedly from mine, but then again I can still spend the last half hour of your day with you reading side-by-side in bed, and one of the biggest kicks of this year was discovering that you, too, enjoy doing the New York Times magazine crosswords and spending several happy evenings hunched over the latest one with you, hungry to fill in the blanks.

But still, I’m having a hard time fully understanding, deep in my gut, the level to which you are, these days, the star of your own show. I’m barely one of the supporting cast, more like caterer and gofer and driver and occasional assistant director or script doctor. I mean, I'm not being humble: I contribute a great deal to the running of the show, but it feels like it's mostly behind-the-scenes work these days.

This is hard for me. Not so much emotionally as psychically, even physically. You go to get yourself a snack or a glass of milk and it surprises me — that you might be hungry and I can’t sense it. I love apples, and yet they make you break out in hives, and still I have the urge to feed you more apples. We organize your Pokémon cards so carefully, because as little as I care for the actual game I do love sorting things. And then you dump out the boxes to find the card you're looking for and leave them splayed across your floor, because as little as you care about organization, you do love the game.

I'm working on this, kid: cutting the cord and all that. I know it's not the way to go through the world with you, nor will it be with your brother, but I console myself with the fact that it must at least be a somewhat normal process, this differentiation. I'm trying to see you for the independent person that you are; paradoxically, it's helping me to understand that personhood by hearkening back to my own self at nine, hopefully using that knowledge, those memories, to grant you more agency. Perhaps it's no coincidence that I am rereading Bridge to Terabithia (I finished it yesterday, gasping and sobbing), learning how to solve the Rubik's cube. What's the world like through your eyes? And what if it's a totally different world than mine, at nine, as your mother?

What if? Well, I suppose we will muddle through as the world continues to rotate on its axis, orbit its way around the sun. You will continue to grow into the person that you already are, and I will continue to watch you do that, and I will try — oh, how I will try — to learn how to see you as your own, lovely, person.